Split screen editing demo

Usage instructions:

1. Check out this PR or branch
2. Start the server as per normal: ``node webodf/httpserver.js``
3. Point a browser towards http://127.0.0.1:8124/webodf/programs/editor/src-splitscreen.html
4. Log in on both clients (no user validation is performed)

# TODO
* [x] Add support for OT
* [x] Pause/play support to interrupt flow between clients
* [x] Quicker login
* [x] Randomise cursor colours to make it easier to see which user is which
* [x] ~~Fix op priorities so it's per memberid~~ (not an existing problem. My understanding here was flawed)
* [x] ~~Let Bella loose in these!~~ (won't happen in this PR)

# Pics
![screenshot from 2014-06-17 18 12 07](https://cloud.githubusercontent.com/assets/1052079/3297694/2b1369a8-f5f7-11e3-8be1-98c4d09247f5.png)

Better use
```
    <script src="dojo-amalgamation.js" data-dojo-config="async: true"></script>
    <link rel="stylesheet" type="text/css" href="app/resources/app.css"/>
```
here instead of CDN, like done for all build editor. Not only because relative links do not work for some reason with dojo, as you will find out once you run the split screen from the build... :rooster: